Got into an accident today..Anyone experienced brakes failure ?

Got into an accident today..Anyone experienced brakes failure ?

Hi Everyone,

I got into an accident today. I am replayed the scenario several times in my head.
I somehow feel the brakes failed on me. I hit the brakes in time and the car had enough room to stop.

Before heading out of home when I sat in my car.. I did get some smoky/burnt smell.
I checked with my kids. They did not smell anything.. so headed out.
I am wondering if its some brake issue.

Anyone else had any such experience ?

Mine is May 2013 Model S P++.


Only Trons | March 1, 2014

Sorry to hear about your accident. Hope no injuries.

There was discussion in TMC thread about perceived loss of braking in wet conditions. Go to the following thread --

2kids10horses | March 1, 2014

The Model S is a heavy car. Lots of forward momentum.

Sorry to hear about the accident. I hope no person was hurt. Cars can be repaired.

sv | March 1, 2014

Yeah... Luckily no one got injured.

Thanks for sharing the link.

I did drive in lot of rain last night. Today morning there was no rain. I think the brakes failed the first time I used them.

Was there any recall on this ?

nick-r | March 1, 2014

About a week ago, I was driving in the rain on the highway. The car in front of me slowed down very suddenly so I had to brake hard. I thought that the brakes had failed because they did not slow down the car very much at all. I avoided an accident, but OMG it scared the bejesus out of me when I discovered the brakes weren't doing their job.

I've driven in the rain plenty of times in many different cars, but these brakes are surprisingly dangerous when wet. I'm convinced we need better brakes due to the weight of this car. Or maybe better brake pads?

sv | March 1, 2014

Will Tesla investigate/help with this ? The car is at the body shop now. All the front of my vehicle is gone.

My car should have sent some diagnostics last night or today before teh accident?

The car did alert the roadside assistance after the accident.

chenglo1 | March 1, 2014

This is downright scary. Recalls anyone? Perhaps larger diameter rotors, calipers and pads? Hope Tesla investigates and takes action soon. This could be detrimental to company appeal not to mention stock value if neglected and results in bad publicity.

Tâm | March 1, 2014


Brake's behaviors change after it got some water.

It might be a good idea to brake a few times at a start a trip.

I got a standard 85 kWh and the brake has worked flawlessly in dry weather (Of course, after a car wash, or in rain, it behaves differently, so I just have to take that into account.)

My car's regenerative braking would take care to make sure I have a safe distance in front of my car in most of situations and when it's still not enough, I would need to apply my foot to the brake.

jbunn | March 1, 2014

Chenglo, Not scary at all. The car has a massive braking system from Brembo. Top of the line stuff. SV, you would not smell a burnt smell from the brakes when the car is in your drive. They are hydraulic brakes with an electrical power assist. Same system as in a conventional car, except instead of a vacuum assist to the brake from engine vacuum, it's an electrical assist pump. If that pump goes out, you'll still have brakes, just like you would in a car if the engine stalled. What's the chance you had your foot on the brake and "gas" pedal at the same time? Do you remember hearing a warning chime? Braking distance on this car is impressive, even for a sports car.

timgostony | March 1, 2014

I'd imagine this has to do with the fact that we use the brakes a lot less than you would in a conventional ICE vehicle. Normally, when it is wet, the brakes are frequently dried each time you apply the brakes to do normal slowing; in the electric car, you let off the gas and use regen to slow down, and the brakes stay wet.

The best thing I can think of at the moment is to just keep a conservative following distance & use the brakes early instead of totally depending on regen during wet weather. (Hopefully going to take my own advice tonight out in rainy LA)

sperber53 | March 1, 2014

Don't blame the brakes for nor keeping enough distance and not paying attention.

Brembo is perhaps the best manufacturer there is, thir disc brakes have proven their effectiveness millions and millions of times in dozens of different cars. The chances that there was something wrong with the driver rather than something wrong with the brakes are about 10.000.000 to 1.

Everyne knows that brakes take a little longer to respond when wet, also that they should be used from time to time to keep them clean and fully effective.

riceuguy | March 1, 2014

Agreed on the Brembo comments...these are amazingly powerful brakes that stop the car in an absurdly short distance for its weight (even for a lighter car). There is nothing special about the car that would make to more prone to brake failure (the brakes are not, for example, some sort of drive by wire brakes. If there was a fault, Tesla can find it in the logs if you request it, but most likely you either hit the gas rather than the brake (much more common than you might think in a panic) or the gas and the brake together (foot placement error).

sperber53 | March 2, 2014

Hitting the brake and the gas together is not possible in a Tesla, as soon as the brake pedal is activated all power to the motor is cut, no matter how hard you step on the power pedal.

Disc brakes where wet and maybe slightly rusty from driving in the rain the night before, driver was not paying attention and not keeping enough distance. Happens thousands of times a day.

Mark E | March 2, 2014

It is possible for the brake pads to be pushed away from the rotors if you hit a large puddle at speed - it's happened to me once in my Porsche (also Brembo brakes). This is not a failure, but is disconcerting as you have to pump the pedal to get feel back again. I've been driving for over 30 years and experienced it only once.

J.T. | March 2, 2014

Model S P ++?

I'm not usually the one to say this but POIDH.

Use of the word "recall".
A response in agreement by "Nick-r"?

I think the burning smell was from under the collar of the people with a short position.
And I do hope they get hurt.

MassX1317 | March 2, 2014

I have read this a few times and it appears it is a result of using the brakes so little. Maybe the sensor for the wipers could let the car know to use brakes in connection with regen braking for the next 5-10 miles after it senses rain. I'm sure Tesla could find a way to to make it feel like there is no difference between the two.

lolachampcar | March 2, 2014

I do not know who SV is so I'll hold off on any comment on the OP.

What I can say without reservation is that MS has some of the best brakes on the planet. It is a 4500+ lb car that out stops my Maranello. Tesla did a fantastic job of leveraging the low Center of Gravity (CoG) such that the rear rotors are larger than the front and the rears contribute significantly to overall stopping power.

Tesla was serious about safety and the brakes are but one example of this commitment.

My old employer had a check box for "Group 7, Equipment not at fault". Perhaps this is an operating condition not recognized by the driver (Rust on Rotors, Pad Knock Back, etc.).

Skjervesbu | March 2, 2014

This problem has been discussed on the Norwegian forum and is real. Pumping the brakes should not be necessary. No need to dismiss every negative comment as a lie or shorter.
Other car manufacturers have systems to take care of this by drying the brakes, and it does not only cover luxury cars.

J.T. | March 2, 2014

The OP has posted before but at that time he was driving an 85P.

Of course, I might be just picking nits and I don't want to minimize the alarm caused by brakes that don't brake, but I would dearly love to see this post made private.

J.T. | March 2, 2014

@Skjervesbu I am not a troll hunter and I am not dismissing the incident but details matter and when a poster cannot accurately report what model of car he is driving it kind of puts a cloud over everything else. It's not my fault for recognizing the inaccuracies.

These are important matters which we all pay close attention to. Detailed, accurate information is essential to remove any reason for doubt.

hsadler | March 2, 2014

'Will Tesla investigate/help with this ? '

Maybe you should ask Tesla and not us for the answer.

After you do finally contact Tesla, be sure to let us know the result and which SC you may be dealing with.

Also, I wasn't aware that the car contacts Roadside Assistance - nice feature.

Emmetpeppers | March 2, 2014

I've driven my car in lots of wet conditions and never experienced any brake issues...I would like to say I have accidentally stepped on both the brake pedal and accelerator pedal at the same time a couple of times over the year I've had it and I suspect that may be what happened here with this accident.

When driving in rain/snow it's always important to be extra cautious no matter what car you drive...don't expect the same break performance in adverse weather conditions as you get on a dry sunny day....keep a little extra space between you and the car in front of you for example.

tes-s | March 2, 2014

No - never experienced any brake failure, or noticed any type of diminished braking in wet conditions or the day after wet conditions.

jordanrichard | March 2, 2014

Perhaps there was some rust build up on the rotors from lack of use and they were wet. Perhaps as preventative measure, for the first few miles one could set the regen to low and there for requiring the use of the brakes for the first few "slow downs". One can easily see through the rims, if there is any rust.

If in fact there was a brake assist failure, it would certainly require more brake effort. However, as others mentioned there would be a fault code.

The only time I have ever smelled the brakes on any car, is either after doing a lot of hard braking (Auto Crossing my 911) or one of the brake calipers locked up. You mentioned smelling burnt when first getting into the car with your kids. Had you just returned from a drive?

GIdoc | March 2, 2014

Not defending the OP but this does seem to be a real issue. I have read the TMC thread and lot of owners seem to have noticed this behavior in wet conditions. I was reading that thread two days ago and thought to myself that wow this is concerning and it is just matter of time before someone doesn't realize this break behavior and gets into an accident!

I am concerned about it because my wife will occationally drive MS too and she is not much of a car person. She won't know about deliberately breaking few time after driving in rain to make sure that breaks work. Our current car has never shown this behavior in wet or rainy condition. Those who do not believe the OP, please do read the TMC thread.

Agree about making the thread private.

Hart | March 2, 2014

A) The brakes are fantastic
B) In wet conditions, you MUST "prime" them a bit before they grip (common sense)
C) Make critical posts such as this one, which question the car's essential safety mechanisms, private!!! Again, that's just common sense given the overblown reaction the the battery fires of the past. Too many powerful Tesla haters out there. If you like your car and believe in the concept - try to help, not hurt! We want to hear about potential problems, but lets first determine if they really are problems before doing damage!

tes-s | March 2, 2014

I don't pump, prime, or do anything to the brakes and have not noticed any issues wet or dry. I press on the brake, and the car stops.

Hart | March 2, 2014

@tes: I don't pump either, but ANY wet brake will have a bit of a lag over a dry brake before max efficiency. Common sense.

Hart | March 2, 2014

A) The brakes are fantastic
B) In wet conditions, you MUST "prime" them a bit before they grip (common sense)
C) Make critical posts such as this one, which question the car's essential safety mechanisms, private!!! Again, that's just common sense given the overblown reaction the the battery fires of the past. Too many powerful Tesla haters out there. If you like your car and believe in the concept - try to help, not hurt! We want to hear about potential problems, but lets first determine if they really are problems before doing damage!

Bighorn | March 2, 2014

It's like riding a bike--water delays initial grip of brakes on wet rim/rotor.

Thomas N. | March 2, 2014

I have a P85 and I use creep so am used to using the brakes at every stop. It has been pouring rain here in SoCal and I've had the car out often.

No issues with the brakes. 60 to 0 just like the pavement was completely dry.

The only reason I hate taking the car out in rain is how dirty it gets. The super aerodynamics destroy the side skirts and rear of the car with dirty spray and requires a car was every single time.

Captain_Zap | March 2, 2014

I live where is sloppy wet. No matter what car I drive I dry out the brakes routinely. That is how I was taught to drive. I found the Model S' braking behavior no different from that of my heavy BMW in the wet.

Olof | March 2, 2014

@sv: what's your VIN nr?

sv | March 2, 2014

Thanks to everyone for your comments.

Typo..Correction on my model: P85+

I did contact Tesla service they said they will be checking the logs.

I have been had my Tesla since may 2013.
I am very proud of its performance.
I myself have talked to people several times about its great acceleration and stopping distance.

But somehow I really felt yesterday, It did not stop in time when I hit the breaks. I felt it kept going more than I am used to.

I did smell smoke in the care before heading out.

frekri | March 2, 2014

There has been Norwegian owners reporting that break fails in wet conditions. When you start your drive they recommend that you should break to remove moisture from the breaks. Some of those has also had this trouble with other brands. The solution is simple if you remember to break. :)

I have not experienced it myself yet and it has been raining since I got my car a week ago.

cfOH | March 2, 2014

Anyone driving a Model S and relying nearly exclusively on regen for stopping/slowing is likely not going to have a good handle on the car's BRAKING (not breaking) performance and may misjudge emergency stopping distances. Add to that the degradation that wet conditions play -- pads are less effective due to reduced friction and ABS may kick in, which can increase stopping distances beyond those that would be experienced under ideal conditions -- and you will likely find a great many Model S owners not being able to control their vehicles adequately. But this is NOT a problem with the car; rather, it's a problem with drivers and their expectations and abilities.

Ohmman | March 2, 2014

This is an interesting argument for keeping creep on in wet conditions. Or just changing behavior.. but I agree the regen limits or eliminates the braking a traditional vehicle would do in the same conditions.

tes-s | March 2, 2014

@hart - perhaps. But I don't notice anything. I just drive, and press on the brake when I need to stop. I don't pump or prime the brakes to dry them off. Not on this car or any of my cars.

And I don't see how the MS differs from an ICE when it comes to brakes - don't they use the same technology for brakes?

jjaeger | March 2, 2014

maybe a side benefit of always driving it like I stole it. Regen gets me slowed down, but on the brake at every stop, as I'm not looking to eke every last whr/mile out of her...

NKYTA | March 2, 2014

Ditto @jjaeger. I've had to stomp the brakes precisely once, on the 405 in LA. Went from 75mph to about 10 very rapidly. Now that we are getting our rains up here in NorCal, I've not noticed any issues.

edcalis | March 2, 2014

That is odd. I never noticed anything wrong with the brakes when wet. Maybe because I never use them.

Tâm | March 2, 2014


If you spray your garden water hose to your 4 brakes, then go to sleep. Wake up and examine the brakes.

Look! They should all RUSTED!

Then spray some more water and take a drive.

The noise might be different and the instant response might be a little lag but not much.

But of course if it's 85mph with the car suddenly stops in front of you, this little difference can be critical.

It is something expected, just like you just can't say that I can make it to the next Supercharger with 8 miles left on dashboard as well as in real distance remained but in subzero temperature, all bet is off!

It's not a defect.

It's a fact that if we don't want to learn ourselves, may be the government needs to send us to a basic braking technique for $5,000 class before you can get to drive. | March 2, 2014


Do you do lot of hard driving/braking? Perhaps your pads had some glazing which contributed to the problem--if you most you regen, you might not have noticed it before.


jbunn | March 2, 2014

Tam has one of the most responsible comments. Consider this...

Ever wonder why jet airplanes don't have windshield wipers? At speed, air pressure pushes the water up and off the window. Now consider your rotors. Centrifugal force flings the water outward and off faster than it can accumulate.

Secondly the gap between the rotor and the pad is so narrow you'd be hard pressed to slip a sheet of paper between the pad and rotor. That means the entire surface of the rotor is scraped clean with every rotation.

Third, neither the rotor or pad are porous and don't retain water. The caliper presses the pad to the rotor so tightly that the water isn't much of an issue after a fraction of a second.

Finally, the thought that regen means you don't use your brakes at all is incorrect. Just backing down your driveway is enough to clean off surface rust. Even with regen on, and creep off, you use your brakes more than you think.

Tricks like turning regen off, ect are well meaning, but not required. At the end of the day, it's still a very high end conventional braking system from an excellent manufacturer.

pilotSteve | March 2, 2014

When then does BMW have a wet brake system that automatically applies brakes when the rain sensor indicates a wet road environment?

I too have been surprised by lack of braking when its wet but fortunately it was just a surprise not close to hitting anything.

Seven years with my BMW 550 and I never felt a difference between wet and dry braking. Of course tire traction is a different matter.

Audi, Cadillac, Mercedes also have brake drying in their top models.

Hopefully Tesla will add this in a future firmware version.

slipdrive | March 2, 2014

I have a 5500 lb SUV and it probably has half the braking power at the Model S. And with the low mass, we don't get the SUV "over throw" and front suspension load when heavy braking. I have to remember the use the brakes moderately every day, or I would just drive around with one foot... This system is awesome in my book.

jbunn | March 2, 2014

I lived in Seattle for over 22 years, and had a number of vehicles including my Tesla before I moved (with the Tesla). I never did notice a difference on any of my vehicles, and never crashed.

I will say that when it's wet out, I allow extra stopping distance. I'm more concerned with losing grip on the road. If it's that wet, you should slow down and allow additional stopping distance for safety.

DC@Tesla | March 2, 2014

1. Drove in heavy rain all last week in California. No brake issues. Brakes are awesome.

2. You can't really drive this car anymore with one foot because regen has been throttled back since last year. Some braking is necessary. So the issue is likely not rusting.

tes-s | March 3, 2014

Regen seems the same to me. Had the car since August.

Theresa | March 3, 2014

I know everyone here seems to jump on posters who post anything bad. But I was one of the owners who had extreme tire wear which appears to have been caused by poor alignment from the day I got the car. And I was jumped all over for my post at that time but have since been accepted as having a real issue.

I also recently had a scare due to the brakes. Since I live in Iowa we get snow and I have been used to cars getting the brakes iced up so I do know how to check and adjust for that.

My incident happened in a parking lot when I was just pulling out of my spot. I don't feel it is related but two days before we had a large snowfall (which tends to freeze up brakes) but my brakes seemed to work well then. At the time of this incident it had warmed to around 30 degrees and had rained most of the day. When I pulled out of my parking space I turned left as I was in the second from the end space. The car just barely gets straightened out at that point where you have to stop for cross traffic. It was at this point where I applied the brakes since there was a vehicle in the cross lane and even though the pedal felt like I was applying the brakes the car acted as though there were no brakes at all. I nearly hit the person. As soon as I got out of that situation I tried the brakes again and they were slightly better but still very weak. I pumped them once more and then they finally felt normal.

Now I am over 50 so I have a few years of experience driving and this is the first time I have had something like this happen to me. I am aware of the situation where the breaks freeze up due to getting wet and then sitting overnight as that happens on my Roadster all the time. But I have never had something like this happen with the Roadster. So I do believe there is something going on that is not quite right.

tes-s | March 3, 2014

@Theresa - when service checked it, did they find anything in the logs, or anything wrong with the brakes?